sys/netinet6/mld6.c

   1 /*      $FreeBSD: src/sys/netinet6/mld6.c,v 1.4.2.4 2003/01/23 21:06:47 sam Exp $       */
   2 /*      $DragonFly: src/sys/netinet6/mld6.c,v 1.6 2005/06/03 19:56:08 eirikn Exp $      */
   3 /*      $KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $   */
   4
   5 /*
   6  * Copyright (C) 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1988 Stephen Deering.
  36  * Copyright (c) 1992, 1993
  37  *      The Regents of the University of California.  All rights reserved.
  38  *
  39  * This code is derived from software contributed to Berkeley by
  40  * Stephen Deering of Stanford University.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)igmp.c      8.1 (Berkeley) 7/19/93
  67  */
  68
  69 #include "opt_inet.h"
  70 #include "opt_inet6.h"
  71
  72 #include <sys/param.h>
  73 #include <sys/systm.h>
  74 #include <sys/mbuf.h>
  75 #include <sys/socket.h>
  76 #include <sys/protosw.h>
  77 #include <sys/syslog.h>
  78 #include <sys/thread2.h>
  79
  80 #include <net/if.h>
  81
  82 #include <netinet/in.h>
  83 #include <netinet/in_var.h>
  84 #include <netinet/ip6.h>
  85 #include <netinet6/ip6_var.h>
  86 #include <netinet/icmp6.h>
  87 #include <netinet6/mld6_var.h>
  88
  89 #include <net/net_osdep.h>
  90
  91 /*
  92  * Protocol constants
  93  */
  94
  95 /* denotes that the MLD max response delay field specifies time in milliseconds */
  96 #define MLD6_TIMER_SCALE        1000
  97 /*
  98  * time between repetitions of a node's initial report of interest in a
  99  * multicast address(in seconds)
 100  */
 101 #define MLD6_UNSOLICITED_REPORT_INTERVAL        10
 102
 103 static struct ip6_pktopts ip6_opts;
 104 static int mld6_timers_are_running;
 105 /* XXX: These are necessary for KAME's link-local hack */
 106 static struct in6_addr mld6_all_nodes_linklocal = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 107 static struct in6_addr mld6_all_routers_linklocal = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 108
 109 static void mld6_sendpkt (struct in6_multi *, int, const struct in6_addr *);
 110
 111 static struct lwkt_token mld6_token = LWKT_TOKEN_INITIALIZER(mp_token);
 112
 113
 114 void
 115 mld6_init(void)
 116 {
 117         static u_int8_t hbh_buf[8];
 118         struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
 119         u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
 120
 121         mld6_timers_are_running = 0;
 122
 123         /* ip6h_nxt will be fill in later */
 124         hbh->ip6h_len = 0;      /* (8 >> 3) - 1 */
 125
 126         /* XXX: grotty hard coding... */
 127         hbh_buf[2] = IP6OPT_PADN;       /* 2 byte padding */
 128         hbh_buf[3] = 0;
 129         hbh_buf[4] = IP6OPT_RTALERT;
 130         hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
 131         bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
 132
 133         init_ip6pktopts(&ip6_opts);
 134         ip6_opts.ip6po_hbh = hbh;
 135 }
 136
 137 void
 138 mld6_start_listening(struct in6_multi *in6m)
 139 {
 140         /*
 141          * RFC2710 page 10:
 142          * The node never sends a Report or Done for the link-scope all-nodes
 143          * address.
 144          * MLD messages are never sent for multicast addresses whose scope is 0
 145          * (reserved) or 1 (node-local).
 146          */
 147         lwkt_gettoken(&mld6_token);
 148         mld6_all_nodes_linklocal.s6_addr16[1] =
 149                 htons(in6m->in6m_ifp->if_index); /* XXX */
 150         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal) ||
 151             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) < IPV6_ADDR_SCOPE_LINKLOCAL) {
 152                 in6m->in6m_timer = 0;
 153                 in6m->in6m_state = MLD6_OTHERLISTENER;
 154         } else {
 155                 mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
 156                 in6m->in6m_timer = MLD6_RANDOM_DELAY(
 157                         MLD6_UNSOLICITED_REPORT_INTERVAL * PR_FASTHZ);
 158                 in6m->in6m_state = MLD6_IREPORTEDLAST;
 159                 mld6_timers_are_running = 1;
 160         }
 161         lwkt_reltoken(&mld6_token);
 162 }
 163
 164 void
 165 mld6_stop_listening(struct in6_multi *in6m)
 166 {
 167         mld6_all_nodes_linklocal.s6_addr16[1] =
 168                 htons(in6m->in6m_ifp->if_index); /* XXX */
 169         mld6_all_routers_linklocal.s6_addr16[1] =
 170                 htons(in6m->in6m_ifp->if_index); /* XXX: necessary when mrouting */
 171
 172         if (in6m->in6m_state == MLD6_IREPORTEDLAST &&
 173             (!IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &mld6_all_nodes_linklocal)) &&
 174             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) > IPV6_ADDR_SCOPE_NODELOCAL)
 175                 mld6_sendpkt(in6m, MLD_LISTENER_DONE,
 176                              &mld6_all_routers_linklocal);
 177 }
 178
 179 void
 180 mld6_input(struct mbuf *m, int off)
 181 {
 182         struct ip6_hdr *ip6;
 183         struct mld_hdr *mldh;
 184         struct ifnet *ifp = m->m_pkthdr.rcvif;
 185         struct in6_multi *in6m;
 186         struct in6_ifaddr *ia;
 187         struct ifmultiaddr *ifma, mark;
 188         struct sockaddr sa;
 189         int timer;              /* timer value in the MLD query header */
 190
 191 #ifndef PULLDOWN_TEST
 192         IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
 193         mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
 194 #else
 195         IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
 196         if (mldh == NULL) {
 197                 icmp6stat.icp6s_tooshort++;
 198                 return;
 199         }
 200 #endif
 201
 202         lwkt_gettoken(&mld6_token);
 203         /* source address validation */
 204         ip6 = mtod(m, struct ip6_hdr *);/* in case mpullup */
 205         if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
 206 #if 0
 207                 log(LOG_ERR,
 208                     "mld6_input: src %s is not link-local (grp=%s)\n",
 209                     ip6_sprintf(&ip6->ip6_src),
 210                     ip6_sprintf(&mldh->mld_addr));
 211 #endif
 212                 /*
 213                  * spec (RFC2710) does not explicitly
 214                  * specify to discard the packet from a non link-local
 215                  * source address. But we believe it's expected to do so.
 216                  * XXX: do we have to allow :: as source?
 217                  */
 218                 m_freem(m);
 219                 lwkt_reltoken(&mld6_token);
 220                 return;
 221         }
 222
 223         /*
 224          * In the MLD6 specification, there are 3 states and a flag.
 225          *
 226          * In Non-Listener state, we simply don't have a membership record.
 227          * In Delaying Listener state, our timer is running (in6m->in6m_timer)
 228          * In Idle Listener state, our timer is not running (in6m->in6m_timer==0)
 229          *
 230          * The flag is in6m->in6m_state, it is set to MLD6_OTHERLISTENER if
 231          * we have heard a report from another member, or MLD6_IREPORTEDLAST
 232          * if we sent the last report.
 233          */
 234         switch(mldh->mld_type) {
 235         case MLD_LISTENER_QUERY:
 236                 if (ifp->if_flags & IFF_LOOPBACK)
 237                         break;
 238
 239                 if (!IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) &&
 240                     !IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
 241                         break;  /* print error or log stat? */
 242                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 243                         mldh->mld_addr.s6_addr16[1] =
 244                                 htons(ifp->if_index); /* XXX */
 245
 246                 /*
 247                  * - Start the timers in all of our membership records
 248                  *   that the query applies to for the interface on
 249                  *   which the query arrived excl. those that belong
 250                  *   to the "all-nodes" group (ff02::1).
 251                  * - Restart any timer that is already running but has
 252                  *   A value longer than the requested timeout.
 253                  * - Use the value specified in the query message as
 254                  *   the maximum timeout.
 255                  */
 256                 IFP_TO_IA6(ifp, ia);
 257                 if (ia == NULL)
 258                         break;
 259
 260                 /*
 261                  * XXX: System timer resolution is too low to handle Max
 262                  * Response Delay, so set 1 to the internal timer even if
 263                  * the calculated value equals to zero when Max Response
 264                  * Delay is positive.
 265                  */
 266                 timer = ntohs(mldh->mld_maxdelay)*PR_FASTHZ/MLD6_TIMER_SCALE;
 267                 if (timer == 0 && mldh->mld_maxdelay)
 268                         timer = 1;
 269                 mld6_all_nodes_linklocal.s6_addr16[1] =
 270                         htons(ifp->if_index); /* XXX */
 271
 272                 bzero(&sa, sizeof(sa));
 273                 sa.sa_family = AF_UNSPEC;
 274                 sa.sa_len = sizeof(sa);
 275
 276                 bzero(&mark, sizeof(mark));
 277                 mark.ifma_addr = &sa;
 278
 279                 /* TODO: need ifnet_serialize_main */
 280                 ifnet_serialize_all(ifp);
 281
 282                 TAILQ_INSERT_HEAD(&ifp->if_multiaddrs, &mark, ifma_link);
 283                 while ((ifma = TAILQ_NEXT(&mark, ifma_link)) != NULL) {
 284                         TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link);
 285                         TAILQ_INSERT_AFTER(&ifp->if_multiaddrs, ifma, &mark,
 286                             ifma_link);
 287
 288                         if (ifma->ifma_addr->sa_family != AF_INET6)
 289                                 continue;
 290                         in6m = (struct in6_multi *)ifma->ifma_protospec;
 291                         if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr,
 292                                         &mld6_all_nodes_linklocal) ||
 293                             IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
 294                             IPV6_ADDR_SCOPE_LINKLOCAL)
 295                                 continue;
 296
 297                         if (IN6_IS_ADDR_UNSPECIFIED(&mldh->mld_addr) ||
 298                             IN6_ARE_ADDR_EQUAL(&mldh->mld_addr,
 299                                                 &in6m->in6m_addr))
 300                         {
 301                                 if (timer == 0) {
 302                                         /*
 303                                          * Release serializer(s) temporarily,
 304                                          * before sending report.
 305                                          */
 306                                         ifnet_deserialize_all(ifp);
 307                                         /* send a report immediately */
 308                                         mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
 309                                                 NULL);
 310                                         ifnet_serialize_all(ifp);
 311                                         in6m->in6m_timer = 0; /* reset timer */
 312                                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 313                                 }
 314                                 else if (in6m->in6m_timer == 0 || /*idle state*/
 315                                         in6m->in6m_timer > timer) {
 316                                         in6m->in6m_timer =
 317                                                 MLD6_RANDOM_DELAY(timer);
 318                                         mld6_timers_are_running = 1;
 319                                 }
 320                         }
 321                 }
 322                 TAILQ_REMOVE(&ifp->if_multiaddrs, &mark, ifma_link);
 323
 324                 ifnet_deserialize_all(ifp);
 325
 326                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 327                         mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
 328                 break;
 329         case MLD_LISTENER_REPORT:
 330                 /*
 331                  * For fast leave to work, we have to know that we are the
 332                  * last person to send a report for this group.  Reports
 333                  * can potentially get looped back if we are a multicast
 334                  * router, so discard reports sourced by me.
 335                  * Note that it is impossible to check IFF_LOOPBACK flag of
 336                  * ifp for this purpose, since ip6_mloopback pass the physical
 337                  * interface to looutput.
 338                  */
 339                 if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
 340                         break;
 341
 342                 if (!IN6_IS_ADDR_MULTICAST(&mldh->mld_addr))
 343                         break;
 344
 345                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 346                         mldh->mld_addr.s6_addr16[1] =
 347                                 htons(ifp->if_index); /* XXX */
 348                 /*
 349                  * If we belong to the group being reported, stop
 350                  * our timer for that group.
 351                  */
 352                 in6m = IN6_LOOKUP_MULTI(&mldh->mld_addr, ifp);
 353                 if (in6m) {
 354                         in6m->in6m_timer = 0; /* transit to idle state */
 355                         in6m->in6m_state = MLD6_OTHERLISTENER; /* clear flag */
 356                 }
 357
 358                 if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 359                         mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
 360                 break;
 361         default:                /* this is impossible */
 362                 log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
 363                 break;
 364         }
 365
 366         m_freem(m);
 367         lwkt_reltoken(&mld6_token);
 368 }
 369
 370 void
 371 mld6_fasttimeo(void)
 372 {
 373         struct in6_multi *in6m;
 374         struct in6_multistep step;
 375
 376         /*
 377          * Quick check to see if any work needs to be done, in order
 378          * to minimize the overhead of fasttimo processing.
 379          */
 380         lwkt_gettoken(&mld6_token);
 381         if (!mld6_timers_are_running) {
 382                 lwkt_reltoken(&mld6_token);
 383                 return;
 384         }
 385
 386         mld6_timers_are_running = 0;
 387         IN6_FIRST_MULTI(step, in6m);
 388         while (in6m != NULL) {
 389                 if (in6m->in6m_timer == 0) {
 390                         /* do nothing */
 391                 } else if (--in6m->in6m_timer == 0) {
 392                         mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
 393                         in6m->in6m_state = MLD6_IREPORTEDLAST;
 394                 } else {
 395                         mld6_timers_are_running = 1;
 396                 }
 397                 IN6_NEXT_MULTI(step, in6m);
 398         }
 399         lwkt_reltoken(&mld6_token);
 400 }
 401
 402 static void
 403 mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
 404 {
 405         struct mbuf *mh, *md;
 406         struct mld_hdr *mldh;
 407         struct ip6_hdr *ip6;
 408         struct ip6_moptions im6o;
 409         struct in6_ifaddr *ia;
 410         struct ifnet *ifp = in6m->in6m_ifp;
 411         struct ifnet *outif = NULL;
 412
 413         /*
 414          * At first, find a link local address on the outgoing interface
 415          * to use as the source address of the MLD packet.
 416          */
 417         if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
 418             == NULL)
 419                 return;
 420
 421         /*
 422          * Allocate mbufs to store ip6 header and MLD header.
 423          * We allocate 2 mbufs and make chain in advance because
 424          * it is more convenient when inserting the hop-by-hop option later.
 425          */
 426         MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
 427         if (mh == NULL)
 428                 return;
 429         MGET(md, MB_DONTWAIT, MT_DATA);
 430         if (md == NULL) {
 431                 m_free(mh);
 432                 return;
 433         }
 434         mh->m_next = md;
 435
 436         mh->m_pkthdr.rcvif = NULL;
 437         mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
 438         mh->m_len = sizeof(struct ip6_hdr);
 439         MH_ALIGN(mh, sizeof(struct ip6_hdr));
 440
 441         /* fill in the ip6 header */
 442         ip6 = mtod(mh, struct ip6_hdr *);
 443         ip6->ip6_flow = 0;
 444         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 445         ip6->ip6_vfc |= IPV6_VERSION;
 446         /* ip6_plen will be set later */
 447         ip6->ip6_nxt = IPPROTO_ICMPV6;
 448         /* ip6_hlim will be set by im6o.im6o_multicast_hlim */
 449         ip6->ip6_src = ia->ia_addr.sin6_addr;
 450         ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
 451
 452         /* fill in the MLD header */
 453         md->m_len = sizeof(struct mld_hdr);
 454         mldh = mtod(md, struct mld_hdr *);
 455         mldh->mld_type = type;
 456         mldh->mld_code = 0;
 457         mldh->mld_cksum = 0;
 458         /* XXX: we assume the function will not be called for query messages */
 459         mldh->mld_maxdelay = 0;
 460         mldh->mld_reserved = 0;
 461         mldh->mld_addr = in6m->in6m_addr;
 462         if (IN6_IS_ADDR_MC_LINKLOCAL(&mldh->mld_addr))
 463                 mldh->mld_addr.s6_addr16[1] = 0; /* XXX */
 464         mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
 465                                      sizeof(struct ip6_hdr),
 466                                      sizeof(struct mld_hdr));
 467
 468         /* construct multicast option */
 469         bzero(&im6o, sizeof(im6o));
 470         im6o.im6o_multicast_ifp = ifp;
 471         im6o.im6o_multicast_hlim = 1;
 472
 473         /*
 474          * Request loopback of the report if we are acting as a multicast
 475          * router, so that the process-level routing daemon can hear it.
 476          */
 477         im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
 478
 479         /* increment output statictics */
 480         icmp6stat.icp6s_outhist[type]++;
 481
 482         ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
 483         if (outif) {
 484                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 485                 switch (type) {
 486                 case MLD_LISTENER_QUERY:
 487                         icmp6_ifstat_inc(outif, ifs6_out_mldquery);
 488                         break;
 489                 case MLD_LISTENER_REPORT:
 490                         icmp6_ifstat_inc(outif, ifs6_out_mldreport);
 491                         break;
 492                 case MLD_LISTENER_DONE:
 493                         icmp6_ifstat_inc(outif, ifs6_out_mlddone);
 494                         break;
 495                 }
 496         }
 497 }